Fire-resistant bituminous compositions



5%? im Msi@ @www f l April 28, 1970 F. WARE 3,508,934

FIRE-RESISTANT BITUMINOUS COMPOSITIONS Filed Feb. 14, 1967 U.S. Cl. 106-15 10 Claims ABSTRACT or THE-DISCLOSURE l This invention is directed to bituminous Atire-resistant compositions comprising felts, asphalt and/or coal tar saturants, inorganic fillers, and a reproong composition comprising a natural-occurring phosphate rock and/ or shale from phosphora formations, deposits or beds having 0.25 to 40% by weight of phosphorous oxide.

This application is a continuation-in-part of applicants copending application Ser. No. 238,861, filed Nov. 20, 1962, now Patent 3,372,040.

This invention is directed to a fire-resistant bituminous composition and more specically to a fire-resistant composition useful for the preparation of sidings and/ or roofs and the like which comprises a bituminous saturant, felt, fillers, and an effective amount of a natural-occurring phosphate rock and/ or'shale.

More specifically, this invention is directed to a bituminous composition comprising a natural-occurring phosphate rock which may be used in the manufacturing of sidings, for home construction, shingles, wrapping and packaging paper, electrical transmission insulations, insulating board, and various other applications utilizing bituminous materials. The composition of this invention is intended to produce a self-extinguishing asphalt or asphalt mixture which will not support combustion and is capable of passing, tests submittedA by the Underwriters Laboratories. f' v It is well known that in determining the suitability of a particular roofing as a re fbarrier, the Underwriters Laboratories have devised certain` tests to show the merit of the roong material. These tests are designated as Classes A, B or C, the order in which they are capable of resisting flame. Thus, for example, in accordance with tests of the Underwriters Laboratories, asphalt roofs or shingles which satisfactorily pass the Class C testmay, however, fail to pass the more severe tests of Classes A and B. The latter two tests are reserved for the highly fire-resistant roofs which usually com-prise asbestos or heavy mineral surface coatings. Under these tests, it is possible to determine whether or not a particular coating or roofing composition will soften and flow when exposed to llames so as to, in effect, act as fuel to the fire. As can be shown by the Flame Propagation test, the burning area spreads rapidly so as to envelope the entire area covered by the roofing. Another test, however, known as the Burning Brand test, when used on most of the presently available roofing compositions, causes the protective granules to erode with the flow of the molten asphalt. Thus, the felt becomes exposed and offers little, if any, protection to the structure.

Accordingly, to avoid these and other problems, it has been found that conventional asphalt roofs or sidings, either in the form of shingles or sheets, may be fireproofed by incorporating in the asphalt saturants an effective amount of a natural-occurring phosphate rock and/or shale having ay particular particle size and containing effective amounts of phosphorous oxide.

Thus, it is an object of this invention to provide a nited States Patent 3,508,934 Patented pr. 28, 1970 ice rooting composition characterized as being non-flowing, flame-resistant, plastic and comprising a predominant amount of a bituminous composition and a roofing felt.

It is another object of this invention to provide a composition for preparing fire-resistant roofs or sidings which will enable the roof so formed to meet certain Underwriters Laboratories requirements with respect to lire resistance unattainable heretofore.

It is a further object of this invention to provide a composition comprising felt, asphalt and/ or coal tar residues as a saturant for the felt in combination with fillers, and an neffective amount of a natural-occurring phosphate rock having an effective amount of phosphorous oxide.

I t is still a further object of this invention to provide a method of imparting name-resistance to bituminous materials, such as asphalt normally used in preparing roofs and sidings.

These and other objects of the invention will become apparent from a further and more detailed discussion as follows.

It has been found, quite unexpectedly, that conventional roong compositions `comprising asphalt and/or coal tar saturants may be rendered lire-resistant by incorporating therein effective amounts of a natural-occurring phosphate rock and/or shale characterized as having 0.25 to 40% by weight of phosphorous oxide calculated on the basis of phosphorous pentaoxide (P205).

More specifically, it has been found that improved fireresistant compositions may be obtained by utilizing a combination of 1 to 90 parts by weight, and more preferably 10 to 60 parts by weight, of a felt material, l5 to 70 parts by weight, and more preferably 30 to 60 parts by weight, of an asphalt and/ or coal tar saturant, 0 to' 30 parts by weight, and more preferably 5 to 15 parts by 4weight of an inorganic i'iller,' e.g., silica, sand and the like, and 5 to 60 parts by Weight, and more preferably 10 to 40 parts by weight of a ilatural-occurring phosphate rock and/or shale obtained from phosphora formations having 0.25 to 40% by Weight of P205.

The felt material used in'lcombination with the other roofing ingredients are conventional materials and may include, for example, various sized fibers obtained from rags, paper, wood, glass fibers, rock wool, asbestos, and mixtures thereof in any relative proportions. These libers and combinations thereof are V'blended in such proportions that the resulting characteristics, i.e., strength, absorption capacity and iiexibility, are suicient to make acceptable rooting products. These felts are readily available and may be characterized, e.g., by weight, tensile strength, flexibility, etc., which enables them to withstand the strain encountered on the roofs and during the manufacturing processes. Moreover, the felts are characterized as having absorption capacities ranging from 11/2 to 2 times their weights. The felts may be made on machinery similar to paper making machines in that the fibers are prepared by various pulping methods, depending upon the source of the material. Thus, for example, rag fibers may be prepared in beaters after the rags are cut and shreaded, which is similar to the preparation of iibers of paper and wood where cooking devices and attrition mills are utilized. The felts may be further characterized in terms of pounds per 480 square feet which is referred to as the felt number which may range from about a No. 21 to 75.

The asphalt and/ or coal tar uxes used as the saturants with the above-mentioned felts are well-known in the industry and may be obtained from petroleum, etc. Thus, the term asphalt used herein may include natural asphalt or asphalts derived from petroleum or coal tar. A typical asphalt known as a penetrating asphalt may have a softening point in the region of about F.,

while the flexible coating asphalts may have softening of this invention, however, may have softening points ranging from about 80 F. to 300 F. and more preferably softening points ranging from about 125 F. to 160 F.

In the manufacture of a roof, it is desirable to construct the body with a sheet of highly absor-bent felt impregnated or saturated with an oil-rich asphalt referred to herein as the saturant. The saturant may be then sealed in with a further application of a more hard, viscous coating asphalt which may, in itself, be protected, if desired, by a covering of outer mineral granules.

In addition to the asphalts or saturants in combination with the felts, various inorganic materials may be incorporated in the asphalt as a -ller in amounts ranging from to 3() parts by weight of the total composition and more preferably, in about 5 to 15 parts by weight of the composition. The amount of the inorganic filler used, if any, may depend upon the amount of the natural-occurring phosphate rock employed. Thus, for example, it is possible to use a mixture of the inorganic filler with the natural-occurring phosphate rock in any relative proportion so long as at least 50% of the mixture comprises the phosphate rock having an effective amount of phosphorous oxide.

The inorganic -llers may include various materials having a particle size ranging from 25 to 325 mesh and more preferably a mesh of 35 to 200, and include, for example, silica, talc, dolomite, lime stone dust, sand, and various mixtures thereof in any relative proportion. It is obvious that by the term inorganic filler, it is intended to include all those materials ordinarily used in asphalt roofing. It has been found that rooting asphalts will resist weathering substantially better and are more resistant to shockproof or changes in weather if they comprise a certainamount of a finely-divided inorganic mineral known as llers or stabilizers.

A typical example of preparing a rooting composition in accordance with this invention comprises the use of a felt which is subjected to a saturating process wherein moisture is eliminated and the bers are filled or saturated as completely as possible with the asphalt saturant. After completion of the saturating process, the saturant is usually present in an excess amount on the surface of the felt sheet. If desired, at this point the phosphate rock or shale may be incorporated onto the felt with the saturant. This sheet is preferably held for a time so that the natural shrinkage of the asphalt upon cooling will cause the excess to be drawn into the felt, resulting in a very high degree of saturation. After saturation of the felt is completed, if the asphalt was applied to both the top and bottom surfaces, a surfacing material, e.g., talc or mica, may be applied to both sides by spreading and passing through a press roll. These mineral surface materials may be colored or color mixtures of granules in combination with the phosphate rock which are spread thickly on the coating asphalt. The coated sheets are then passed through a series of press and cooling drums in order to insure proper impregnation of the outer granules into the sheet which is then subjected to a controlled pressure to force the granules in the coating to the desired depth.

When it is desirable to prepare shingles from the abovementioned prepared asphalt composition, the material is fed from the finishing machinery into a shingle cutting machine. Here, the sheet is cut to the desired shape and size and then separated into units which are accumulated in stacks of the proper number for packaging.

The natural-occurring phosphate rock of this invention is incorporated in the rooting material either alone or in combination with the inorganic llers or stabilizer in the prescribed amount sufficient to impart to the felt and asphalt combination, re resistance capable of passing the Underwriters Laboratory tests. The naturaloccurring phosphate and/or shale may be pulverized to particle sizes such, for example, that 100% passes through a 27 mesh screen and approximately 4% passes through a 325 mesh screen. Thus, it is preferred for purposes of this invention to use particle sizes of the natural-occuring phosphate rock ranging from 25 to 325 mesh. The particle sizes and amount of the naturaloccurring phosphate rock used in combination with the asphalt and felt will depend upon the amount of P205 content in said rock. Thus, for example, when the P205 content is approximately 35% by weight, it is only necessary to use 10% by weight or less of the rock in combination with the asphalt and felt. If, however, the P205 in the rock is present in smaller amounts, then it is obvious that larger percentages, eg., up to 60%, of the rock may be used in combination with the asphalt and felt. It was unexpected to ind that the phosphorous oxide, herein calculated as P205, Was the effective ingredient of the natural-occurring phosphate rock which imparted fire-resistance to the asphalt compositions. The natural-occurring phosphate rock ranging from 25 to 325 this invention, may be found in phosphoria formations and deposits in the western part ofr the country or in the phosphate beds of the southern states, such as Florida and Tennessee, but more particularly in the western states, such as Montana. The phosphate ore or rock from Montana may contain approximately 10% by weight of distillable oil which may be utilized as the saturant in the manufacturing of the fire-resistant siding and rooting compositions of this invention, with the rock per se being used as the re retardant.

A more specific description of the naturally-occurring rock and shale may be identified by the chart referred to herein as FIGURE 1 which has an index map that gives the location of a specific phosphoria formation. The chart is an illustration of a stratographic section showing the location of the entire phosphoria formation from Big Sheep Canyon to Indian Creek, for a total of about 74 miles. The phosphoria is divided into units, namely, E, D, C, B, and A. These formations have rock and shale sections containing from about 0.25 to 40% by weight of P205. A particular cut A in Unit D at Sawtooth Mountain, point 12 to the index map, shows the exact location as it presently exists in the southern part of the State of Montana. The vertical depth of 'Unit D is approximately 60 feet and comprises the phosphate rock, mudstone, and minor amounts of dolomite and chert.` The exact composition of cut A of Unit D was found to have the following analyses:

TABLE I.CUT A Percent Assay o. U Th P205 Width Description 12 0.001 0. 2 0. 25 Slurnp Chert.

11 0. 001 0. 1 0. 50 3 Argilleeeous siltstone.

14. 0. 001 0.2 30. 91 3" Phosphate rock.

10 .001 0.2 18. 79 126. Phosphate shale.

13 0 003 0.2 27.05 25 Phosphate rock.

9 0.002 0.2 11. 16 184 Black shale seams with a 6 seam of pure phosphate rock, the shale section being highly petrollferous.

8 0.001 0.1 l 47 24 Sltstone.

7 0. 001 0. 2 8. 68 81- Petroliierous shale.

6 0. 003 0. 1 2. 06 22 Petroliferous siltstone.

5. 0.003 0. 2 9. 73 49 Phosphatic shale etrolierous Witli 3 seam o phosphate roc 4 0. 001 0.2 3. 16 23 Siltstone.

3 0.002 0.2 10. 73 8 6 Black oolltic phosfphate rock which is petroll erous.

2. 0.005 0. 1 30. 59 13 Phosphate rock, slightly petroliferous.

1 0. 002 0.2 28. 14 15" Petroliferous phosphate rock.

In addition to the U, Th, and P205 content of the above-described Cut A, as shown in the graph of the Phosphoria formation of Unit D at Sawtooth Mountain (12), the following chemical analyses also were obtained.

TABLE IL ANALYSES ORE Sample 1 2 3 4 5 6 7 8 9 10 11 12 13 14 CaO A1103 S101 P105 MgO P105 F2103 F8101 P105 A1101 A1101 Fe10| Mso MgO

ZnO ZnO LOW, .1l-1% N010 B101 Low/Very Low, .G-.5% o

A1103 Tl01 Very Low, .0l-.1%

Mgo Nio Bios zro, Very Low/Trace, .005-.5% SIO Trace, Less than .01%

The phosphoria in the southwestern part of Montana of felt and asphalt until a built-up roof is obtained which is shown to be divided into five groups in an ascendis capable of passing the Classes A and B Underwriters ing order of sandstone dolomite, a thin phosphatic 40 tests. In these tests, the roofing or asphalt shingle with shale, a sandstone dolomite chert, an upper phosphatic or Without the surface granules is placed at an angle shale, anda chert quartz sandstone. The upper phos- 30 and an oxyacetylene flame having a temperature phatic shale member, or Unit D as indicated in the of about 2000 F. is positioned at right angles to the chart and more specifically in the table, is particularly shingle so that the tip of the ame touches or is in rich in phosphate rock and shale which contain higher 45 contact therewith. If the flame fails to burn through percentages of P305. Unit D contains phosphate rock the shingle in about two minutes, the shingle will succomprisingto 20% of a carbonate liuoro-apatite. cessfully pass the Class A Underwriters test. The asphalt The mudstone of this unit may contain as much as compositions utilizing the lower softening point materials to v% organic matter, about 10% of which is a distillrequire a greater amount of the fire-resistant phosphate able oil. rock, while therasphalts having the higher softening points Commercially this phosphate rock is available as one require a lesserfV amount of the tire-resistant rock deor more phosphate minerals, primarily calcium phospending, of course, upon the amount of P205 present. By phate, but may inciude phosphitizedlimestone, sandinterdispersingthe P205 containing roclr-`l throughout the stone, shale, and other forms of phosphate rock. While asphalt saturii't', the amount of combustible material in these phosphate materials do not have a delinite chemicontact with the llame is minimized andthe rock Serves cal structure, the major minerals are of the apatite as a barrier between the ames and the combustible group andare represented by the formula asphalt.

As indicated above, the tire-resistant agent is blended CadpodcoahcloI-Ih with the molten asphalt in the same manner as previously wherein in some instances the phosphate radical 1s re- 60 used for inorganic fillers with conventional equipment. placed with Small quantities of metal oxides and the The asphalt including Trinidad asphalt, coal tar, pitch,

allions, i, ilumine, may be a Combination 0f llOrDe, etc., and mixtures thereof, are blended with the fillers,

chlorine, and hydroxyl ions, or any one alone. In ade.g., limestone, clay, slate, etc., in the required propordition, small quantities of calcium may be replaced by tions and applied to the surfaces to be protected including, elements, Such as magnesium, manganese, strontium, lead, for example, saturated roofing felts.

sodium, uranium, oerium, and yitrium. Other impurities Particular examples which illustrate the bituminous include iron as limonite, clay, aluminum Phosphate, compositions of this invention are given below.,

liu'orine, andA silica as quartz. v

The phosphate rock of this invention may be used EXAMPLE I in combination with mopping asphalts or liexible asphalt 1 Parts by weight coating compositions which ordinarily have softening Felt, e.g., glass fibers, etc lto 90 points in the region of about 225 F. Here, the roofs Asphalt or coal-tar saturant 15 to 70 are prepared by laying the base felt onto the surface Fillers, e.g., sand, mica, talc or the like Oto 30 which is subsequently covered with the mopping asphalt Natural-occurring phosphate rock 0.25 to 40% comprising the phosphate rock which is used in layers by weight of P205 (2S-325 mesh) 5 to 60 7 EXAMPLE II Dry felt Saturant (asphalt) 25 Inorganic filler 5 Phosphate rock (29.8% P205) (200 mesh) 60 EXAMPLE III Dry felt, e.g., glass fibers 25 Asphalt saturant 40 Phosphate rock 35 The relative proportions of the ingredients as illustrated above will depend obviously upon the type of roof being .prepared whether asphalt shingles or a mopping asphalt, etc., and will vary depending upon the amount of fire retardant, i,e., P205, ingredient in the particular phosphate rock being used.

Roofs and sidings prepared by the above-described bitu- .minous compositions may be further characterized as not liquefying under the application of heat to flow from its base when placed on slopes up to 50 and which retain the particular granule materials during exposure to the ame until substantially all of the organic binder is burned. Moreover, the composition forms hard, continuous crosslike surfaces upon being exposed to flame and after being burned out, retains a cohesive ash capable of withstanding high air velocities. This ash protection further inhibits the spread of the flame on roofs even when the ame is fanned up to 20 miles per hour. Moreover, asphalt roofs have been found to resist cracking under thermal stress and strains set-up during the burning of the roofing surfaces when covered with the bituminous compositions of this invention.

While this invention has been described with respect to a num-ber of specific embodiments, it is obvious that there are other variations and modifications which can be employed without departing from the spirit of the invention, as particularly pointed out in the appended claims.

What is claimed is:

1. A bituminous composition for preparing fire-resistant sidings and roofs which comprises 1 to 90 parts by weight of a felt, to 70 parts by weight of an asphalt or coal tar saturant, 0 to 30 parts by weight of an inorganic liller and 5 to 60 parts by weight of a natural-occurring phosphate rock having a particle size ranging between 25 to 325 mesh; said phpsphatefrrock characterized as having 0.25 to 40% by weight of phosphorous oxide as a fireu retarding ingredient.

2. The composition of claim 1 further characterized in that the felt is selected from the class consisting of bers of rags, paper, wood, glass, rock wool, asbestos, and mixtures thereof.

3. The composition of claim 1 further characterized in 8 that a filler is present in the asphalt saturant in amounts ranging from 5 to 15 parts by weight.

4. The composition of claim 1 further characterized in that the natural-occuring phosphate rock is present in amounts of 10 to 40 parts by weight and is characterized as having 5 to 30% by weight of phosphorous pentaoxide.

5. The composition of claim 4 further characterized in that the saturant has a softening point ranging from about F. to 260 F.

6. A process of imparting flame-resistance to asphaltfelt rooting compositions which comprises incorporating therein 5 to 60 parts by weight of a natural-occurring phosphate rock having a particle size between 25 and 325 mesh; said phosphate rock characterized as having 0.25 to 40% by weight of phosphorous pentaoxide as a tireretarding ingredient.

7. The process of claim 6 further characterized in that the felt is selected from the class consisting of bers 0r rags, paper, wood, glass, rock wool, asbestos, and mixtures thereof.

8. The process of claim 7 further characterized in that the asphalt is present in an amount of 15 to 70 parts by weight and the felt is present in an amount ranging from 1 to 90 parts by weight.

9. The process of claim 8 further characterized in that the asphalt has a softening point ranging from about 125 F. to 260 F.

10. The process of claim 9 further characterized in that the natural-occurring phosphate rock is present in an amount ranging from about 10 to 40 parts by weight of the asphalt and felt and has a phosphorous pentaoxide content ranging from 5 to 30%.

References Cited UNITED STATES PATENTS 878,912 2/1908 Timofeeff 106109 1,937,292 11/1933 Moore 106-110 2,090,625 8/1937 Edwards 106-109 2,272,576 2/1942 Penn 252-81 X 2,303,463 12/1942 Horne 106*109 2,569,399 9/1951 Burns et al. 106-282 2,632,743 3/1953 Eckert 106-15 X 3,249,534 5/1966 Ware 252-8.1

FOREIGN PATENTS 500,416 2/1939 Great Britain,

JULIUS FROME, Primary Examiner J. B. EVANS, Assistant Examiner U.S. C1. X.R. 

